At Polyface Farm, Sheri Salatin, daughter-in-law of Joel Salatin and marketing director at the farm, has seen firsthand the growing interest in sustainable farming from the youngest generations.

Critics worry that the retail giant will "Wal-Mart" organic food, pushing farms to relocate to unregulated regions abroad.

Despite a recent study that says organic food offers little nutritional advantage, Jill Stein explains why organic agriculture is still a vital approach.